The present invention provides aryl or heteroaryl substituted benzofuran derivatives, and more specifically, provides compounds of formula (I) as described hereinbelow. These compounds are 5-HT ligands, and are useful for treating diseases wherein modulation of 5-HT activity is desired.
Serotonin has been implicated in a number of diseases and conditions that originate in the central nervous system. These include diseases and conditions related to sleeping, eating, perceiving pain, controlling body temperature, controlling blood pressure, depression, anxiety, schizophrenia, and other bodily states. R. W. Fuller, Biology of Serotonergic Transmission, ed. Neville V. Osborne, John Wiley and Sons (1982), p 221; D. J. Boullin, Serotonin in Mental Abnormalities 1, John Wiley and Sons (1978), p. 316; J. Barchas, et al., Serotonin and Behavior, Academic Press, New York, N.Y. (1973). Serotonin also plays an important role in peripheral systems, such as the gastrointestinal system, where it has been found to mediate a variety of contractile, secretory, and electrophysiologic effects.
As a result of the broad distribution of serotonin within the body, there is a tremendous interest in drugs that affect serotonergic systems. In particular, receptor-specific agonists and antagonists are of interest for the treatment of a wide range of disorders, including anxiety, depression, hypertension, migraine, obesity, compulsive disorders, schizophrenia, autism, neurodegenerative disorders (e.g. Alzheimer""s disease, Parkinsonism, and Huntington""s chorea), and chemotherapy-induced vomiting. M. D. Gershon, et al., The Peripheral Actions of 5-Hydroxytryptamine, 246 (1989); P. R. Saxena, et al., Journal of Cardiovascular Pharmacology, 15:Supplement 7 (1990).
The major classes of serotonin receptors (5-HT1-7) contain fourteen to eighteen separate receptors that have been formally classified. See Glennon, et al., Neuroscience and Behavioral Reviews, 1990, 14, 35; and D. Hoyer, et al. Pharmacol. Rev. 1994, 46, 157-203. Recently discovered information regarding subtype identity, distribution, structure, and function suggests that it is possible to identify novel, subtype specific agents, having improved therapeutic profiles (e.g. fewer side effects).
For example, the 5-HT2 family of receptors is comprised of 5-HT2A, 5-HT2B, and 5-HT2C subtypes, which have been grouped together on the basis of primary structure, secondary messenger system, and operational profile. All three subtypes are G-protein coupled, activate phospholipase C as a principal transduction mechanism, and contain a seven-transmembrane domain structure. There are distinct differences in the distribution of the three 5-HT2 subtypes. The 5-HT2B and 5-HT2A receptors are widely distributed in the periphery, while the 5-HT2C receptor has been found only in the central nervous system, being highly expressed in many regions of the human brain. See G. Baxter, et al. Trends in Pharmacol. Sci. 1995, 16, 105-110.
Subtype 5-HT2A has been associated with effects including vasoconstriction, platelet aggregation, and bronchoconstriction, while subtype 5-HT2C has been associated with diseases that include depression, anxiety, obsessive compulsive disorder, panic disorders, phobias, psychiatric syndromes, and obesity. Very little is known about the pharmacologic role of the 5-HT2B receptor. See F. Jenck, et al., Exp. Opin. Invest. Drugs, 1998, 7, 1587-1599; M. Bos, et al., J. Med. Chem., 1997, 40, 2762-2769; J. R. Martin, et al., The Journal of Pharmacology and Experimental Therapeutics, 1998, 286, 913-924; S. M. Bromidge, et al., J. Med. Chem., 1998, 41,1598-1612; G. A. Kennett, Drugs, 1998, 1, 4, 456-470; and A. Dekeyne, et al., Neuropharmacology, 1999, 38, 415-423.
Japanese Patent Application S63-149645 discusses a vast genus of compounds that are reported to be useful to prevent photochemical browning of organic pigments. The compounds specifically prepared in the application differ considerably in structure from the compounds of the invention. For example, they lack a benzofuran type ring system.
U.S. Pat. No. 5,616,575 relates to tricyclic ibogaine analogs of the following formula. 
The compounds are reported to be useful to treat cocaine addiction and the use of other addictive substances. The compounds differ from the compounds of the invention at the groups R2 and R3 in the above formula.
There is currently a need for pharmaceutical agents that are useful to treat diseases and conditions associated with 5-HT receptors.
In accordance with the present invention, novel compounds that demonstrate useful biological activity, and particularly activity as 5-HT receptor ligands, are provided. Thus, the present invention provides a compound of formula (I): 
wherein:
R1, R2, R3, and R4 are independently hydrogen, halo, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, xe2x80x94C1-8alkyl, xe2x80x94C3-8cycloalkyl, xe2x80x94OR8, xe2x80x94NR8R9, xe2x80x94SR8, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, or xe2x80x94C1-8alkylene(heteroaryl);
R5 is hydrogen, C1-8alkyl, haloC1-8alkyl, C3-8cycloalkyl, C1-8alkanoyl, haloC1-8alkanoyl, xe2x80x94C(xe2x95x90O)OR8, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, or xe2x80x94C1-8alkylene(heteroaryl);
R6 is hydrogen or C1-4alkyl;
each R8 and R9 is independently hydrogen, C1-8alkyl, haloC1-8alkyl, C3-8cycloalkyl, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, xe2x80x94C1-8alkylene(heteroaryl) or R8 and R9 together with the nitrogen to which they are attached form a pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino ring;
m is 0, 1, or 2;
n is 1 or 2;
X is oxy (xe2x80x94Oxe2x80x94), thio (xe2x80x94Sxe2x80x94) xe2x80x94S(xe2x95x90O)xe2x80x94 or xe2x80x94SO2xe2x80x94;
the bond represented by xe2x80x94 is absent or present; and
wherein any C1-8alkyl, C1-8alkylene, C1-8alkoxy or C3-8cycloalkyl of R1, R2, R3, R4, R5, R6, R8 and R9 is optionally partially unsaturated; and
wherein any aryl or heteroaryl of R1, R2, R3, R4, R5, R8 or R9 is optionally substituted with one or more (e.g., 1, 2, 3, or 4) substituents independently selected from halo, xe2x80x94CN, xe2x80x94NO2, xe2x80x94CF3, xe2x80x94OCF3, C1-8alkyl, C2-8alkenyl, C2-8alkynyl, C3-8cycloalkyl, C3-8cycloalkenyl, aryl, heteroaryl, xe2x80x94ORc, xe2x80x94SRc, xe2x80x94C(xe2x95x90O)Rc, xe2x80x94CO2Rc, xe2x80x94C(xe2x95x90O)NRcRd, xe2x80x94NRcC(xe2x95x90O)Rd, xe2x80x94NRcRd, xe2x80x94NRcC(xe2x95x90O)NRcRd, xe2x80x94SO2xe2x80x94NRcRd or xe2x80x94SO2Rc;
wherein each Rc and Rd is independently hydrogen, C1-8alkyl, C1-8alkanoyl, C1-8alkoxycarbonyl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)aryl, xe2x80x94C(xe2x95x90O)oaryl, heteroaryl, xe2x80x94C1-8alkylene(heteroaryl), xe2x80x94C(xe2x95x90O)heteroaryl, xe2x80x94C(xe2x95x90O)oheteroaryl or Rc and Rd together with the nitrogen to which they are attached form a pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino ring;
or a pharmaceutically acceptable salt thereof.
In another aspect, the present invention also provides:
a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient (the composition preferably comprises a therapeutically effective amount of the compound or salt),
a method for treating a disease or condition in a mammal (e.g. a human) wherein a 5-HT receptor is implicated and modulation of a 5-HT function is desired comprising administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof to the mammal,
a method for treating or preventing a disease or disorder of the central nervous system in a mammal comprising administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof to the mammal,
a compound of formula (I) or a pharmaceutically acceptable salt thereof for use in medical diagnosis or therapy (e.g. the treatment or prevention of 5-HT related disease such as anxiety, obesity, depression, or a stress-related disease),
the use of a compound of formula (I), or a pharmaceutically acceptable salt thereof to prepare a medicament useful for treating or preventing a disease or disorder of the central nervous system in a mammal, and
a method for modulating the function of a 5-HT receptor, comprising contacting the receptor with an effective modulatory amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof.
The invention also provides novel intermediates and processes disclosed herein that are useful for preparing compounds of formula (I).
The present invention provides a compound of formula (I): 
wherein:
R1, R2, R3, and R4 are independently hydrogen, halo, xe2x80x94CF3, xe2x80x94OCF3, xe2x80x94CN, xe2x80x94NO2, xe2x80x94C1-8alkyl, xe2x80x94C3-8cycloalkyl, xe2x80x94OR8, xe2x80x94NR8R9, xe2x80x94SR8, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-18alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, or xe2x80x94C1-8alkylene(heteroaryl);
R5 is hydrogen, C1-8alkyl, haloC1-8alkyl, C3-8cycloalkyl, C1-8alkanoyl, haloC1-8alkanoyl, xe2x80x94C(xe2x95x90O)OR8, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, or xe2x80x94C1-8alkylene(heteroaryl);
R6 is hydrogen or C1-4alkyl;
each R8 and R9 is independently hydrogen, C1-8alkyl, haloC1-8alkyl, C3-8cycloalkyl, xe2x80x94C(xe2x95x90O)aryl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)heteroaryl, heteroaryl, xe2x80x94C1-8alkylene(heteroaryl) or R8 and R9 together with the nitrogen to which they are attached form a pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino ring;
m is 0, 1, or 2;
n is 1 or 2;
X is oxy (xe2x80x94Oxe2x80x94), thio (xe2x80x94Sxe2x80x94) xe2x80x94S(xe2x95x90O)xe2x80x94 or xe2x80x94SO2xe2x80x94;
the bond represented by xe2x80x94 is absent or present; and
wherein any C1-8alkyl, C1-8alkylene, C1-8alkoxy or C3-8cycloalkyl of R1, R2, R3, R4, R5, R6, R8 and R9 is optionally partially unsaturated; and
wherein any aryl or heteroaryl of R1, R2, R3, R4, R5, R8 or R9 is optionally substituted with one or more (e.g., 1, 2, 3, or 4) substituents independently selected from halo, xe2x80x94CN, xe2x80x94NO2, xe2x80x94CF3, xe2x80x94OCF3, C1-8alkyl, C2-8alkenyl, C2-8alkynyl, C3-8cycloalkyl, C3-8cycloalkenyl, aryl, heteroaryl, xe2x80x94ORc, xe2x80x94SRc, xe2x80x94C(xe2x95x90O)Rc, xe2x80x94CO2Rc, xe2x80x94C(xe2x95x90O)NRcRd, xe2x80x94NRcC(xe2x95x90O)Rd, xe2x80x94NRcRd, xe2x80x94NRcC(xe2x95x90O)NRcRd, xe2x80x94SO2xe2x80x94NRcRd or xe2x80x94SO2Rc;
wherein each Rc and Rd is independently hydrogen, C1-8alkyl, C1-8alkanoyl, C1-8alkoxycarbonyl, aryl, xe2x80x94C1-8alkylene(aryl), xe2x80x94C(xe2x95x90O)aryl, xe2x80x94C(xe2x95x90O)aryl, heteroaryl, xe2x80x94C1-8alkylene(heteroaryl), xe2x80x94C(xe2x95x90O)heteroaryl, xe2x80x94C(xe2x95x90O)heteroaryl or Rc and Rd together with the nitrogen to which they are attached form a pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino ring;
or a pharmaceutically acceptable salt thereof.
In another aspect, the present invention also provides:
a pharmaceutical composition comprising a compound of formula (I), or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable excipient (the composition preferably comprises a therapeutically effective amount of the compound or salt),
The compounds of the invention are useful for treating or preventing diseases or disorders of the central nervous system. Specific diseases or disorders of the central nervous system for which a compound of formula (I) may have activity include, but are not limited to: obesity, depression, schizophrenia, schizophreniform disorder, schizoaffective disorder, delusional disorder, a stress-related disease (e.g. general anxiety disorder), panic disorder, a phobia, obsessive compulsive disorder, post-traumatic-stress syndrome, immune system depression, a stress induced problem with the urinary, gastrointestinal or cardiovascular system (e.g., stress incontinence), neurodegenerative disorders, autism, chemotherapy-induced vomiting, hypertension, migraine, headaches, cluster headaches, sexual dysfunction in a mammal (e.g. a human), addictive disorder and withdrawal syndrome, an adjustment disorder, an age-associated learning and mental disorder, anorexia nervosa, apathy, an attention-deficit disorder due to general medical conditions, attention-deficit hyperactivity disorder, behavioral disturbance (including agitation in conditions associated with diminished cognition (e.g., dementia, mental retardation or delirium)), bipolar disorder, bulimia nervosa, chronic fatigue syndrome, conduct disorder, cyclothymic disorder, dysthymic disorder, fibromyalgia and other somatoform disorders, generalized anxiety disorder, an inhalation disorder, an intoxication disorder, movement disorder (e.g., Huntington""s disease or Tardive Dyskinesia), oppositional defiant disorder, peripheral neuropathy, post-traumatic stress disorder, premenstrual dysphoric disorder, a psychotic disorder (brief and long duration disorders, psychotic disorder due to medical condition, psychotic disorder NOS), mood disorder (major depressive or bipolar disorder with psychotic features) seasonal affective disorder, a sleep disorder, a specific development disorder, agitation disorder, selective serotonin reuptake inhibition (SSRI) xe2x80x9cpoop outxe2x80x9d syndrome or a Tic disorder (e.g., Tourette""s syndrome).
The following definitions are used, unless otherwise described: halo is fluoro, chloro, bromo, or iodo. Alkyl, alkoxy, etc. denote both straight and branched groups; but reference to an individual radical such as xe2x80x9cpropylxe2x80x9d embraces only the straight chain radical, a branched chain isomer such as xe2x80x9cisopropylxe2x80x9d being specifically referred to. When alkyl, alkylene or cycloalkyl can be partially unsaturated, the alkyl chain or cycloalkyl ring may comprise one or more (e.g., 1, 2, 3, or 4) double or triple bonds in the chain.
Aryl denotes a phenyl radical or an ortho-fused bicyclic carbocyclic radical having about nine to ten ring atoms in which at least one ring is aromatic. Heteroaryl denotes a radical of a monocyclic aromatic ring containing five or six ring atoms consisting of carbon and 1, 2, 3, or 4 heteroatoms each selected from the group consisting of non-peroxide oxygen, sulfur, and N(X) wherein X is absent or is H, O, C1-4alkyl, phenyl or benzyl, as well as a radical of an ortho-fused bicyclic heterocycle of about eight to ten ring atoms derived therefrom, particularly a benz-derivative or one derived by fusing a propylene, trimethylene, or tetramethylene diradical thereto.
It will be appreciated by those skilled in the art that compounds of the invention having a chiral center may exist in and be isolated in optically active and racemic forms. Some compounds may exhibit polymorphism. It is to be understood that the present invention encompasses any racemic, optically-active, polymorphic, tautomeric, or stereoisomeric form, or mixture thereof, of a compound of the invention, which possesses the useful properties described herein, it being well known in the art how to prepare optically active forms (for example, by resolution of the racemic form by recrystallization techniques, by synthesis from optically-active starting materials, by chiral synthesis, or by chromatographic separation using a chiral stationary phase) and how to determine 5-HT activity using the standard tests which are well known in the art.
The carbon atom content of various hydrocarbon-containing moieties is indicated by a prefix designating the minimum and maximum number of carbon atoms in the moiety, i.e., the prefix Ci-j indicates a moiety of the integer xe2x80x9cixe2x80x9d to the integer xe2x80x9cjxe2x80x9d carbon atoms, inclusive. Thus, for example, C1-6alkyl refers to alkyl of one to six carbon atoms, inclusive.
The compounds of the present invention are generally named according to the IUPAC or CAS nomenclature system. Abbreviations which are well known to one of ordinary skill in the art may be used (e.g. xe2x80x9cPhxe2x80x9d for phenyl, xe2x80x9cMexe2x80x9d for methyl, xe2x80x9cEtxe2x80x9d for ethyl, xe2x80x9chxe2x80x9d for hour or hours and xe2x80x9crtxe2x80x9d for room temperature).
Specific and preferred values listed below for radicals, substituents, and ranges, are for illustration only; they do not exclude other defined values or other values within defined ranges for the radicals and substituents.
Specifically, C1-8alkyl can be methyl, ethyl, propyl, isopropyl, butyl, iso-butyl, sec-butyl, pentyl, 3-pentyl, hexyl, heptyl or octyl; C1-3alkyl can be methyl, ethyl, propyl, isopropyl; haloC1-3alkyl can be trifluoromethyl, chloromethyl, 2-chloroethyl, 2,2,2-trifluoroethyl, or perfluoroethyl; haloC1-3alkoxy can be trifluoromethoxy, or 2,2,2-trifluoroethoxy; C1-8alkoxy can be methoxy, ethoxy, propoxy, isopropoxy, butoxy, iso-butoxy, sec-butoxy, pentoxy, 3-pentoxy, hexyloxy, heptyloxy or octyloxy; C1-8alkanoyl can be acetyl, propanoyl, butanoyl, pentanoyl, 4-methylpentanoyl, hexanoyl, heptanoyl or octanoyl; C1-8alkoxycarbonyl can be methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, pentoxycarbonyl, or hexyloxycarbonyl, heptyloxycarbonyl or octyloxycarbonyl; C1-8alkanoyloxy can be acetoxy, propanoyloxy, butanoyloxy, isobutanoyloxy, pentanoyloxy, hexanoyloxy, heptanoyloxy or octanoyloxy; aryl can be phenyl, indenyl, or naphthyl; and heteroaryl can be furyl, imidazolyl, triazolyl, triazinyl, oxazoyl, isoxazoyl, thiazolyl, isothiazoyl, pyrazolyl, pyrrolyl, pyrazinyl, tetrazolyl, pyridyl, (or its N-oxide), thienyl, pyrimidinyl (or its N-oxide), indolyl, isoquinolyl (or its N-oxide) or quinolyl (or its N-oxide).
A specific value for R2 is aryl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc, xe2x80x94SRc, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R2 is phenyl, optionally substituted with one or more substituents independently selected from halo, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc, xe2x80x94SRc, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R2 is phenyl, optionally substituted with one or more substituents independently selected from halo, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy or thioC1-6alkyl.
Another specific value for R2 is phenyl, substituted with one or more substituents independently selected from halo, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy or thioC1-6alkyl.
Another specific value for R2 is phenyl, substituted with one or more substituents independently selected from fluoro, chloro, bromo, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, isopropoxy or thiomethyl.
Another specific value for R2 is phenyl substituted at the 2- and the 6-position with halo independently selected from fluoro, chloro and bromo.
Another specific value for R2 is phenyl substituted at the 2- or the 6-position with fluoro, chloro or bromo.
Another specific value for R2 is phenyl substituted at the 2- and the 4-position with halo independently selected from fluoro, chloro and bromo.
Another specific value for R2 is phenyl substituted at the 2- or the 4-position with fluoro, chloro or bromo.
Another specific value for R2 is phenyl substituted at the 2-, 4- and 6-position with halo independently selected from fluoro, chloro and bromo.
Another specific value for R2 is 2,4-dichlorophenyl, 2,4,6-trichlorophenyl or 2,6-difluoro-4-chlorophenyl.
Another specific value for R2 is heteroaryl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc, xe2x80x94SRc, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R2 is heteroaryl, optionally substituted with one or more substituents independently selected from halo, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc or xe2x80x94SRc.
Another specific value for R2 is heteroaryl, optionally substituted with one or more substituents independently selected from fluoro, chloro, bromo, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
Another specific value for R2 is heteroaryl, substituted with one or more substituents independently selected from fluoro, chloro, bromo, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
A specific value for R1 is hydrogen, C1-3alkyl, halo, haloC1-3alkyl, C1-3alkoxy, haloC1-3alkoxy, or xe2x80x94NR8R9.
Another specific value for R1 is hydrogen or C1-3alkyl.
A specific value for R3 is hydrogen, C1-3alkyl, aryl, halo, haloC1-3alkyl, C1-3alkoxy, haloC1-3alkoxy or xe2x80x94NR8R9.
A specific value for R3 is hydrogen, C1-3alkyl or aryl.
Another specific value for R3 is hydrogen or C1-3alkyl.
A specific value for R4 is C1-8alkyl, xe2x80x94OR8, xe2x80x94SR8, xe2x80x94NR8R9, aryl or xe2x80x94C1-8alkylene(aryl), wherein the aryl groups are optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
A specific value for R4 is C1-8alkyl, xe2x80x94OR8, xe2x80x94SR8, xe2x80x94NR8R9, or aryl, wherein aryl is substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
A specific value for R4 is methyl, ethyl, propyl, isopropyl, butyl, ethylpropyl, cyclohexyl, phenyl, benzyl, methoxy, ethoxy, propoxy, isopropoxy, butoxy, (ethylpropyl)oxy, (cyclohexyl)oxy, phenoxy, (benzyl)oxy, methylthio, ethylthio, propylthio, isopropylthio, butylthio, (ethylpropyl)thio, (cyclohexyl)thio, phenylthio or (benzyl)thio or xe2x80x94NR8R9, wherein R8 is hydrogen, methyl, ethyl, propyl or cyclohexyl and R9 is methyl, ethyl, propyl, cyclohexyl or phenyl; or R8 and R9 together with the nitrogen to which they are attached form a pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino ring.
A specific value for R4 is xe2x80x94NR8R9, wherein R8 is hydrogen, methyl, ethyl, propyl or cyclohexyl and R9 is methyl, ethyl, propyl, cyclohexyl or phenyl.
A specific value for R4 is xe2x80x94NR8R9, wherein R8 is hydrogen, methyl or ethyl and R9 is methyl, ethyl, propyl, cyclohexyl or phenyl.
A specific value for R4 is xe2x80x94NR8R9, wherein R8 is hydrogen, methyl, ethyl or cyclohexyl and R9 is methyl, ethyl, cyclohexyl or phenyl.
A specific value for R4 is xe2x80x94NR8R9, wherein R8 is methyl, ethyl or cyclohexyl and R9 is methyl, ethyl or cyclohexyl.
A specific value for R4 is pyrrolidino, piperidino, azepano, piperazino, morpholino, or thiomorpholino.
A specific value for R5 is hydrogen, C1-8alkyl, C2-8alkenyl, C2-8alkynyl, C3-8cycloalkyl, or C3-8cycloalkenyl, aryl, xe2x80x94C1-8alkylene(aryl), heteroaryl or xe2x80x94C1-8alkylene(heteroaryl).
A group of compounds of Formula I includes compounds where at least one of R1, R3, R2, and R4 is aryl optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc, xe2x80x94SRc, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
A group of compounds of Formula I includes compounds where at least one of R1, R3, R2, and R4 is aryl optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, xe2x80x94ORc, xe2x80x94SRc, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd, and at least two of R1, R3, R2, and R4 are other than hydrogen.
A specific value for R5 is hydrogen or C1-8alkyl
A specific value for R5 is aryl, heteroaryl, xe2x80x94C1-8alkylene(aryl) or xe2x80x94C1-8alkylene(heteroaryl).
A specific value for R5 is hydrogen, methyl, ethyl, benzyl, or phenethyl.
Another specific value for R5 is hydrogen.
A specific value for R6 is hydrogen.
A specific compound of formula (I) is a compound wherein m is 1 and n is 1.
A specific compound of formula (I) is a compound wherein m is 0; n is 1; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 1; n is 1; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 2; n is 1; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 0; n is 2; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 1; n is 2; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 2; n is 2; and X is oxy.
A specific compound of formula (I) is a compound wherein m is 0; n is 1; and X is thio.
A specific compound of formula (I) is a compound wherein m is 1; n is 1; and X is thio.
A specific compound of formula (I) is a compound wherein m is 2; n is 1; and X is thio.
A specific compound of formula (I) is a compound wherein m is 0; n is 2; and X is thio.
A specific compound of formula (I) is a compound wherein m is 1; n is 2; and X is thio.
A specific compound of formula (I) is a compound wherein m is 2; n is 2; and X is thio.
A specific compound of formula (I) is a compound wherein the bond represented byxe2x80x94is absent, and R1, R2, R3, R4, R5, R6, m, and n have any of the values, specific values, more specific values, or preferred values described herein.
A specific compound of formula (I) is a compound having the formula (II): 
wherein R1, R2, R3, R4, R5, R6, m, and n have any of the values, specific values, more specific values, or preferred values described herein.
A specific compound of formula (I) is a compound wherein the bond represented byxe2x80x94is present, and R1, R2, R3, R4, R5, R6, m, and n have any of the values, specific values, more specific values, or preferred values described herein.
A specific compound of the present invention is a compound of formula (III): 
wherein:
R11 is aryl or heteroaryl;
R12 is hydrogen, halo, cyano, C1-3alkyl, haloC1-3alkyl, C1-3alkoxy, haloC1-3alkoxy, or xe2x80x94NRaRb;
R13 is hydrogen, C1-6alkyl, arylC1-6alkyl, or aryloxyC1-6alkyl;
m is 0, 1, or 2;
n is 1 or 2;
X is oxy (xe2x80x94Oxe2x80x94) or thio (xe2x80x94Sxe2x80x94);
the bond represented byxe2x80x94is absent or present; and
Ra and Rb are each independently hydrogen, C1-6alkyl, aryl, (aryl)C1-6alkyl, heteroaryl, or (heteroaryl)C1-6alkyl; or Ra and Rb together with the nitrogen to which they are attached form a pyrrolidino, piperidino, morpholino, or thiomorpholino ring;
wherein any aryl or heteroaryl of R11, R12, R13, Ra, or Rb is optionally substituted with one or more (e.g. 1, 2, 3, or 4) substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd,;
wherein each Rc and Rd is independently hydrogen, C1-6alkyl, C1-6alkanoyl, C1-6alkoxycarbonyl, aryl, (aryl)C1-6alkyl, arylcarbonyl, or aryloxycarbonyl; or Rc and Rd together with the nitrogen to which they are attached form a pyrrolidino, piperidino, morpholino, or thiomorpholino ring;
or a pharmaceutically acceptable salt thereof.
A specific compound of formula (III) is a compound wherein the bond represented byxe2x80x94is absent, and R11, R12, R13, m, and n have any of the values, specific values, more specific values, or preferred values described herein.
A specific compound of formula (III) is a compound wherein the bond represented by xe2x80x94 is present, and R11, R12, R13, m, and n have any of the values, specific values, more specific values, or preferred values described herein.
A specific value for R11 is aryl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R11 is phenyl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R11 is phenyl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, or C1-6alkoxy.
Another specific value for R11 is phenyl, substituted with one or more substituents independently selected from halo, hydroxy, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, or C1-6alkoxy.
Another specific value for R11 is phenyl, substituted with one or more substituents independently selected from fluoro, chloro, bromo, hydroxy, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
Another specific value for R11 is heteroaryl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, nitro, trifluoromethyl, trifluoromethoxy, C1-6alkyl, C1-6alkoxy, phenyl, xe2x80x94NRcRd, or xe2x80x94C(xe2x95x90O)NRcRd.
Another specific value for R11 is heteroaryl, optionally substituted with one or more substituents independently selected from halo, hydroxy, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, or C1-6alkoxy.
Another specific value for R11 is heteroaryl, optionally substituted with one or more substituents independently selected from fluoro, chloro, bromo, hydroxy, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
Another specific value for R11 is heteroaryl, substituted with one or more substituents independently selected from halo, hydroxy, cyano, trifluoromethyl, trifluoromethoxy, C1-6alkyl, or C1-6alkoxy.
Another specific value for R1 1 is heteroaryl, substituted with one or more substituents independently selected from fluoro, chloro, bromo, hydroxy, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
A more specific value for R11 is phenyl, optionally substituted with one or more substituents independently selected from fluoro, chloro, bromo, hydroxy, trifluoromethyl, trifluoromethoxy, methoxy, ethoxy, propoxy, or isopropoxy.
A specific value for R12 is hydrogen or C1-3alkyl.
Another specific value for R12 is halo, haloC1-3alkyl, C1-3alkoxy, haloC1-3alkoxy, or xe2x80x94NRaRb.
A specific value for R13 is C1-6alkyl, arylC1-6alkyl, or aryloxyC1-6alkyl.
Another specific value for R13 is hydrogen.
Another specific value for R13 is C1-6alkyl.
Another specific value for R13 is arylC1-6alkyl or aryloxyC1-6alkyl.
A more specific value for R13 is hydrogen, methyl, ethyl, phenyl, or benzyl.
Specifically, the invention also provides a method for treating or preventing anxiety, obesity, depression, schizophrenia, a stress-related disease (e.g. general anxiety disorder), panic disorder, a phobia, obsessive compulsive disorder, post-traumatic-stress syndrome, immune system depression, a stress induced problem with the gastrointestinal or cardiovascular system, or sexual dysfunction in a mammal (e.g. a human) comprising administering a therapeutically effective amount of a compound of formula (I), or a pharmaceutically acceptable salt thereof to the mammal.
Specifically, the invention also provides a method of treating or preventing anxiety, obesity, depression, or a stress-related disease, comprising administering to a mammal (e.g. a human) in need of such treatment, a therapeutically effective amount of a compound of formula (I) or a pharmaceutically acceptable salt thereof.
Specifically, the invention also provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof to prepare a medicament for treating or preventing anxiety, obesity, depression, schizophrenia, a stress-related disease (e.g. general anxiety disorder), panic disorder, a phobia, obsessive compulsive disorder, post-traumatic-stress syndrome, immune system depression, a stress induced problem with the gastrointestinal or cardiovascular system, or sexual dysfunction in a mammal (e.g. a human).
Specifically, the invention also provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof to prepare a medicament for treating or preventing anxiety, obesity, depression, or a stress-related disease in a mammal (e.g. a human).
The invention also provides processes useful for preparing compounds of formula (I). Accordingly, the invention provides:
a method for preparing a compound of formula (I) wherein the bond represented byxe2x80x94is absent comprising reducing a corresponding compound of formula (I) wherein the bond represented byxe2x80x94is present (as illustrated in Scheme 1 below);
a method for preparing a compound of formula (I) wherein R1 is hydrogen, comprising deprotecting a corresponding compound of formula (I) wherein R1 is a suitable nitrogen protecting group (as illustrated in Scheme 2 below); and
a method for preparing a compound of formula (I) wherein R1 is other than hydrogen, comprising alkylating or acylating a corresponding compound of formula (I) wherein R1 is hydrogen with the requisite alkylating or acylating agent.
Suitable nitrogen protecting groups, as well as methods for their preparation and removal are well known in the art, for example, see Greene, T. W.; Wutz, P. G. M. xe2x80x9cProtecting Groups In Organic Synthesisxe2x80x9d third edition, 1999, New York, John Wiley and sons, Inc. Preferred protecting groups include benzyloxycarbonyl (CBZ), tert-butoxycarbonyl (BOC), and benzoyl.
The invention also provides novel intermediates disclosed herein that are useful for preparing compounds of formula (I). For example, the invention provides an intermediate compound of formula (I) wherein R1 is a suitable nitrogen protecting group.
Compounds of the invention can generally be prepared using synthetic techniques that are known in the art. They can also be prepared using the synthetic procedures illustrated in Schemes 1 and 2 below. Starting materials can be prepared by procedures described in these schemes or by procedures that would be well known to one of ordinary skill in organic chemistry. The variables used in the Schemes are as defined below or as in the claims. It is understood that other compounds of formula (I) can be prepared using procedures similar to those illustrated in the Schemes by modifying the starting materials or by performing additional steps to modify the products.
Compounds of formula (I) can be prepared by reactions outlined in Scheme 1. 
Bromosalicylaldehyde, I-1, is treated with ethyl bromoacetate in the presence of a base, such as potassium carbonate, in an appropriate solvent, such as dimethyl formamide, at elevated temperature to yield bromoindole-2-carboxylic acid ethyl ester, I-2. See for example A E Jakobs, L E Christiaens, M J Renson, Tetrahedron 50(31) 9315-24 (1994). The ethyl ester I-2 is treated with a reducing agent, such as NaBH4, in an appropriate solvent, such as tetrahydrofuran, at room temperature to yield alcohol I-3. See for example International Patent Application Publication Number WO 9734885 A1. The alcohol I-3 is treated with an activating agent, such as methane sulfonyl chloride, in the presence of a base, such as triethylamine, in an appropriate solvent, such as methylene chloride at low temperature. The activated intermediate is treated with appropriate reagents, such as trimethylsilylcyanide and tetrabutylammonium fluoride, in an appropriate solvent, such as acetonitrile, at elevated temperature to yield the nitrile I-4. See for example E D Soli, A S Manoso, M C Patterson, P DeShong, D A Favor, R Hirschmann, A B Smith, J. Org. Chem. 64 3171-7 (1999). Nitrile I-4 is converted to aryl substituted benzofuran nitrile I-5 by means of an appropriate coupling reaction, such as the Suzuki coupling reaction. See for example N Miyaura, A Suzuki, Chem. Rev. 95 2457-83 (1995). The nitrile I-4 is reacted with an appropriately substituted phenylboronic acid in the presence of an appropriate catalyst, such as dichlorobis(triphenylphosphine)-palladium (II), and an appropriate base, such as aqueous sodium carbonate (2N), in an appropriate solvent, such as benzene, at elevated temperature to yield aryl substituted benzofuran nitrile I-5. Benzofuran nitrile I-5 is treated with a reducing agent, such as borane dimethylsulfide complex, in an appropriate solvent, such as tetrahydrofuran, at elevated temperature to yield amine I-6. See for example R Perrone, F Berardi, N A Colabufo, M Leopoldo, V Tortorella, J. Med. Chem. 43(2) 270-7 (2000). Amine I-6 is treated with formaldehyde or an equivalent under acidic conditions to yield the tetrahydrobenzofuropyridine I-7, which is a compound of the invention. See for example N Sotomayor, et. al., Tetrahedron 51 12159-68 (1995). Tetrahydrobenzofuropyridine I-7 is reduced with a reducing agent, such as potassium borohydride, in an appropriate solvent, such as trifluoroacetic acid, to yield hexahydrobenzofuropyridine I-8, which is also a compound of the invention. See for example L N Borisova, G S Rozenberg, N F Kucherova, V A Zagorevskii, Chemistry of Heterocyclic Compounds 17(9) 869-71 (1981).
Compounds of formula (I) can also be prepared by reactions outlined in Scheme 2. 
O-Phenylhydroxylamine is reacted with 4-piperidone in the presence of an acid catalyst, such as hydrochloric acid, in an appropriate solvent, such as 2-propanol, at elevated temperature to yield tetrahydrobenzofuropyridine II-1. See for example International Patent Application Publication Number WO 0037466 A1.
Tetrahydrobenzofuropyridine II-1 is treated with a reducing agent, such as H2 and an appropriate catalyst, such as Pearlman""s catalyst (20% Pd(OH)2 on carbon), in an appropriate solvent, such as 1:1:1 acetic acid:ethanol:water at room temperature to yield hexahydrobenzofuropyridine II-2. See for example P. J. Coleman, et al., Tetrahedron Lett., 2000, 41, 5803-5806. The amino nitrogen of compound II-2 is protected with a suitable protecting group, such as t-butyl carbamate (Boc), by reaction with di-tert-butyl dicarbonate in the presence of a base, such as potassium carbonate, in an appropriate solvent, such as a mixture of water and tetrahydrofuran at room temperature to yield hexahydrobenzofuran II-3 (R=tert-butoxy). Compound II-3 is halogenated with a halogenating agent, such as bromine, in an appropriate solvent, such as chloroform, at room temperature to yield halogenated hexahydrobenzofuran II-4 (Z=halo). Compound II-4 is converted to an aryl or heteroaryl substituted hexahydrobenzofuropyridine II-5 (R1=aryl or heteroaryl) by means of an appropriate coupling reaction such as the Suzuki coupling reaction. See for example N Miyaura, A Suzuki, Chem. Rev. 95 2457-83 (1995). Compound II-4 is reacted with an appropriately substituted phenylboronic acid in the presence of an appropriate catalyst, such as dichlorobis(triphenylphosphine)palladium (II), and an appropriate base, such as aqueous sodium carbonate (2N), in an appropriate solvent, such as benzene, at elevated temperature to yield compound II-5. Compound II-5 is treated with an acid, such as trifluoroacetic acid, at room temperature to deprotect the nitrogen and provide amine II-6, which is a compound of the invention.
In cases where compounds are sufficiently basic or acidic to form stable nontoxic acid or base salts, administration of the compounds as salts may be appropriate. Examples of pharmaceutically acceptable salts are organic acid addition salts formed with acids that form a physiological acceptable anion, for example, tosylate, methanesulfonate, acetate, citrate, malonate, tartarate, succinate, benzoate, ascorbate, xcex1-ketoglutarate, and xcex1-glycerophosphate. Suitable inorganic salts may also be formed, including hydrochloride, sulfate, nitrate, bicarbonate, and carbonate salts.
Pharmaceutically acceptable salts may be obtained using standard procedures well known in the art, for example by reacting a sufficiently basic compound such as an amine with a suitable acid affording a physiologically acceptable anion. Alkali metal (for example, sodium, potassium or lithium) or alkaline earth metal (for example calcium) salts of carboxylic acids can also be made.
Compounds of the present invention can conveniently be administered in a pharmaceutical composition containing the compound in combination with a suitable excipient. Such pharmaceutical compositions can be prepared by methods and contain excipients which are well known in the art. A generally recognized compendium of such methods and ingredients is Remington""s Pharmaceutical Sciences by E. W. Martin (Mark Publ. Co., 15th Ed., 1975). The compounds and compositions of the present invention can be administered parenterally (for example, by intravenous, intraperitoneal or intramuscular injection), topically, orally, or rectally.
For oral therapeutic administration, the active compound may be combined with one or more excipients and used in the form of ingestible tablets, buccal tablets, troches, capsules, elixirs, suspensions, syrups, wafers, and the like. Such compositions and preparations should contain at least 0.1% of active compound. The percentage of the compositions and preparations may, of course, be varied and may conveniently be between about 2 to about 60% of the weight of a given unit dosage form. The amount of active compound in such therapeutically useful compositions is such that an effective dosage level will be obtained.
The tablets, troches, pills, capsules, and the like may also contain the following: binders such as gum tragacanth, acacia, corn starch or gelatin; excipients such as dicalcium phosphate; a disintegrating agent such as corn starch, potato starch, alginic acid and the like; a lubricant such as magnesium stearate; and a sweetening agent such as sucrose, fructose, lactose or aspartame or a flavoring agent such as peppermint, oil of wintergreen, or cherry flavoring may be added. When the unit dosage form is a capsule, it may contain, in addition to materials of the above type, a liquid carrier, such as a vegetable oil or a polyethylene glycol. Various other materials may be present as coatings or to otherwise modify the physical form of the solid unit dosage form. For instance, tablets, pills, or capsules may be coated with gelatin, wax, shellac or sugar and the like. A syrup or elixir may contain the active compound, sucrose or fructose as a sweetening agent, methyl and propylparabens as preservatives, a dye and flavoring such as cherry or orange flavor. Of course, any material used in preparing any unit dosage form should be pharmaceutically acceptable and substantially non-toxic in the amounts employed. In addition, the active compound may be incorporated into sustained-release preparations and devices.
The compounds or compositions can also be administered intravenously or intraperitoneally by infusion or injection. Solutions of the active compound or its salts can be prepared in water, optionally mixed with a nontoxic surfactant. Dispersions can also be prepared in glycerol, liquid polyethylene glycols, triacetin, and mixtures thereof and in oils. Under ordinary conditions of storage and use, these preparations contain a preservative to prevent the growth of microorganisms.
Pharmaceutical dosage forms suitable for injection or infusion can include sterile aqueous solutions or dispersions or sterile powders comprising the active ingredient which are adapted for the extemporaneous preparation of sterile injectable or infusible solutions or dispersions, optionally encapsulated in liposomes. In all cases, the ultimate dosage form should be sterile, fluid and stable under the conditions of manufacture and storage. The liquid carrier or vehicle can be a solvent or liquid dispersion medium comprising, for example, water, ethanol, a polyol (for example, glycerol, propylene glycol, liquid polyethylene glycols, and the like), vegetable oils, nontoxic glyceryl esters, and suitable mixtures thereof. The proper fluidity can be maintained, for example, by the formation of liposomes, by the maintenance of the required particle size in the case of dispersions or by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars, buffers or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin.
Sterile injectable solutions can be prepared by incorporating the active compound in the required amount in the appropriate solvent with various of the other ingredients enumerated above, as required, followed by filter sterilization. In the case of sterile powders for the preparation of sterile injectable solutions, the preferred methods of preparation are vacuum drying and the freeze drying techniques, which yield a powder of the active ingredient plus any additional desired ingredient present in the previously sterile-filtered solutions.
For topical administration, the present compounds may be applied in pure form, i.e., when they are liquids. However, it will generally be desirable to administer them to the skin as compositions or formulations, in combination with a dermatologically acceptable carrier, which may be a solid or a liquid.
Useful solid carriers include finely divided solids such as talc, clay, microcrystalline cellulose, silica, alumina and the like. Useful liquid carriers include water, alcohols or glycols or water-alcohol/glycol blends, in which the present compounds can be dissolved or dispersed at effective levels, optionally with the aid of non-toxic surfactants. Adjuvants such as fragrances and additional antimicrobial agents can be added to optimize the properties for a given use. The resultant liquid compositions can be applied from absorbent pads, used to impregnate bandages and other dressings, or sprayed onto the affected area using pump-type or aerosol sprayers. Thickeners such as synthetic polymers, fatty acids, fatty acid salts and esters, fatty alcohols, modified celluloses or modified mineral materials can also be employed with liquid carriers to form spreadable pastes, gels, ointments, soaps, and the like, for application directly to the skin of the user.
Useful dosages of the compounds of formula (I) can be determined by comparing their in vitro activity, and in vivo activity in animal models. Methods for the extrapolation of effective dosages in mice, and other animals, to humans are known to the art; for example, see U.S. Pat. No. 4,938,949.
The compound is conveniently administered in unit dosage form; for example, containing about 0.05 mg to about 500 mg, conveniently about 0.1 mg to about 250 mg, most conveniently, about 1 mg to about 150 mg of active ingredient per unit dosage form. The desired dose may conveniently be presented in a single dose or as divided doses administered at appropriate intervals, for example, as two, three, four or more sub-doses per day. The sub-dose itself may be further divided, e.g., into a number of discrete loosely spaced administrations.
The compositions can conveniently be administered orally, sublingually, transdermally, or parenterally at dose levels of about 0.01 to about 150 mg/kg, preferably about 0.1 to about 50 mg/kg, and more preferably about 0.1 to about 10 mg/kg of mammal body weight.
For parenteral administration the compounds are presented in aqueous solution in a concentration of from about 0.1 to about 10%, more preferably about 0.1 to about 7%. The solution may contain other ingredients, such as emulsifiers, antioxidants or buffers.
The exact regimen for administration of the compounds and compositions disclosed herein will necessarily be dependent upon the needs of the individual subject being treated, the type of treatment and, of course, the judgment of the attending practitioner.
The ability of a compound of the invention to act as a 5-HT receptor agonist or antagonist can also be determined using in vitro and in vivo assays that are known in the art. The invention provides compounds of formula (I) that act as either agonists or as antagonists of one or more 5-HT receptor subtypes. The compounds of the invention are 5-HT ligands, which typically displace  greater than 50% of a radiolabeled test ligand from one or more 5-HT receptor subtype at a concentration of 1 xcexcM. The procedures used for testing such displacement are well known and would be readily available to one skilled in the art. For example, see L. W. Fitzgerald et al., Mol. Pharmacol, 2000, 57, 1, 75-81; and D. B. Wainscott, et al., J. Pharmacol Exp Ther, 1996, 276, 2, 720-727.
The invention will now be illustrated by the following non-limiting Examples.